Fluid operated devices

ABSTRACT

A fluidic switching device comprising a liquid globule in one chamber of a generally hourglass-shaped structure is adapted, via a vent associated with the chambers and via common input connections, to function as a binary counter, an oscillator, or as two stages of a ring counter. A pulsed input provides binary counter operation, and a continuous input provides oscillation of the liquid globule between the hourglass chambers.

United States Patent (72] Inventor I PcterJ. Campbell 3,438,384 4/1969Hurvitz 137/81.5 Columbus, Ohio 3,450,340 6/1969 Reader 235/ I me 1 1 PP7883409 OTHER REFERENCES med Fluid Decimal Counter," D. J. Truslove,1.B.M. Technical pa'emed 0' 1 B n r 1 s N 3 A 1963 2627 [73] AssigneeBell Telephone Laboratories, Incorporated u e (copy Murray Hm BerkeleyHeigms NJ in Scien. Lib. & Gp. 282, 235 201m.e.)

Fluid Binary Memory Cell A. E. Mitchell ct al., IBM. TechnicalDisclosure Bulletin, vol. 8, No. 3, Aug., 1965, pp. [54] FLUID OPERATEDDEVICES 429, 430. (copy in Scien. Lib. & Gp. 282, 235- 20lm.e.)

4 Chill", 4 Drawing 8 Primary Examiner-Samuel Scott 52 us. Cl. l37/8L5,Attorneys-R Guemher and Kenneth Hamlin 235/201 [51] IIILCI F156 3/06 Fltof Search ..I l37/8L5; ABSTRACT: A fluidic switching device comprising aliquid i 235/201 globule in one chamber of a generally hourglass-shapedstruc- 56 R t Ci ed ture is adapted, via a vent associated with thechambers and l l e t via common input connections, to function as abinary UNITED STATES PATENTS counter, an oscillator, or as two stages ofa ring counter. A 3,151,623 10/1964 Riordan 235/201me pulsed inputprovides binary counter operation, and a con- 3,17l,915 3/1965 Johnson137/81.5X tinuous input provides oscillation of the liquid globule3,181,546 5/1965 Boothe 137/81.5 between the hourglass chambers.

VENT

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FLUID OPERATED DEVICES This invention relates to fluid operated devicesand, more particularly, to fluid pressure operated switching devicesadapted to perform various logic functions.

Fluid pressure operated devices are typically of two types; theso-called pure fluid devices having no moving elements, and fluiddevices having moving elements. In the latter devices the movingelements may be, for example, sliding members, rotating valves, liquidglobules, or the like. Fluid devices with moving elements areparticularly useful where increased system stability is desired.Additionally, the moving elements in such devices can be employedadvantageously to manifest various forms of output signals, such as forinterfacing with other systems, for signaling, or for visual display.Thus, displacement of the moving element under control of fluid pressurecan reveal or conceal a light beam, for example, or, if the movingelement is of a conductive material, displacement thereof can make orbreak electrical connections.

The major disadvantages of known moving element fluid devices concernthe relative complexity and the number of moving elements required toprovide certain basic logic functions such as binary counting.

SUMMARY OF THE INVENTION A principal object of this invention,therefore, is to provide a simple, economical and reliable movingelement, fluid pressure operated binary counter.

A further object of this invention is to provide a simple, economicaland reliable fluid pressure operated device which is adaptable intandemly connected combinations to function as a shift register or aring counter.

In an illustrative embodiment of the present invention, the above andother objects are attained through the use of a fluid pressure operated,two-state switching device comprising two compartments or chambersinterconnected with one another through a restricted passage in themanner, for example, of an hourglass-shaped structure. One of thecompartments contains a globule of liquid, which may be electricallyconductive material such as mercury, of sufficient quantity and ofsufficiently high surface tension to prevent free movement of thematerial through the restricted passage. Sensing apparatus is disposedin at least one of the two compartments to provide an outputmanifestation of the position of the liquid globule. For example,assuming the liquid globule to be conductive material, the sensingapparatus advantageously includes a pair of electrical contacts disposedin one of the compartments so as to be bridged by the conductivematerial when the material is in the one compartment, thereby providingan electrical connection between the bridged pair of contacts.

Individual input fluid pressure paths are associated with each of thecompartments and are connected, for example, to fluid logic circuitry.Increasing the fluid pressure in one of the input fluid pressure pathseffects transfer of the liquid globule from the compartment associatedwith the one path through the restricted passage to the othercompartment.

In accordance with one aspect of my invention, the input fluid pressurepaths to the two compartments are connected to a common input path, anda vent path is associated with the two compartments. The vent path isadapted to vent or decrease the input fluid pressure in the emptycompartment, that is, the compartment not containing the liquid globule,until transfer of the globule from the other compartment through therestricted passage has at least been initiated. Thus, successive fluidpressure pulses applied to the common input path effects transfer of theliquid globule back and forth between the two compartments to providebinary counter operation.

According to a further aspect of my invention three or more suchcompartments may be connected advantageously in tandem to provide shiftregister or ring counter operation. Individual input fluid pressurepaths associated with each compartment are connected to a common inputpath, successive input fluid pressure pulses advancing the liquidglobule through successive ones of the tandemly connected compartments.Sensing apparatus associated with each compartment provides an outputmanifestation of the particular compartment in which the liquid globuleis positioned.

BRIEF DESCRIPTION OF THE DRAWING The above and other objects andfeatures of the invention may be fully apprehended from the followingdetailed description and the accompanying drawing in which:

FIG. 1 shows an illustrative embodiment of a basic two-state fluidpressure operated switching'device in accordance with the principles ofmy invention;

FIG. 2 shows an alternative illustrative embodiment of a two-state fluidpressure operated switching device according to the principles of myinvention;

FIG. 3 shows another alternative illustrative embodiment of a fluidpressure operated switching device according to my inventionparticularly adapted to function as an oscillator; and

FIG. 4 shows an illustrative embodiment of a fluid pressure operatedring counter in accordance with the principles of my invention.

DETAILED DESCRIPTION OF THE INVENTION In the illustrative embodiment ofa two-state fluidic switching device, shown in FIG. 1, two compartmentsor chambers I00 and 102 are interconnected with one another through arestricted passage 105. One of the compartments of the switching device,such as compartment 100, contains a globule of liquid 107 which ispreferably nonwetting and which is of sufficient quantity and ofsufficiently high surface tension to prevent free movement of theglobule through the restricted passage 105.

Sensing apparatus is disposed in one or, as shown in FIG. 4, in both ofcompartments 101 and 102 to provide an output manifestation of theposition of liquid globule 107. For example, assuming the liquid globuleto be of a conductive material such as mercury, the sensing apparatusmay comprise a pair of electrical contacts 120 and 121 disposed incompartment and a pair of electrical contacts 122 and 123 disposed incompartment 102, as shown illustratively in FIG. 1. Contacts 120 and 121are bridged by globule 107 when the globule is in compartment 100 so asto provide an output manifestation thereof at terminals I30 in the formof an electrical connection between contacts 120 and 121. Similarly,when globule 107 is in compartment 102, contacts 122 and 123 areelectrically bridged to provide an output manifestation at terminals132.

Individual input fluid pressure paths 110 and 112 are associated withswitching device compartments 100 and 102, respectively. Increasing thefluid pressure in one of input fluid pressure paths I10 and 112 effectstransfer of liquid globule 107 from the switching device compartmentassociated with the one fluid pressure path through restricted passage105 into the other switching-device compartment. For example, if thefluid pressure in fluid pressure path is increased sufficiently,relative to the pressure in fluid pressure path 112, globule 107 will beurged through restricted passage 105 into compartment 102.

However, in accordance with my invention, input fluid pressure paths 110and 112 are connected to a common input path 150 which, in turn, may beconnected, for example, to fluid logic circuitry (not shown).lncreasing'the fluid pressure in common input path 150, therefore,increases the fluid pressure in both of paths 110 and 112 to respectivecompartments 100 and 102. Vent path 115 isassociated with compartmentsI00 and 102 and is adaptedto vent or decrease the inputfluid pressure inthe empty one of compartments 100 and 102, that is, the compartment inwhich globule 107 is not located.

Thus, when an input fluid pressure pulse, illustratively on the order of0.2 to 2 p.s.i. and having a duration onthe order of l to IDmilliseconds, is applied to common input path and extended over paths110 and 112 to compartments 100 and 102, vent path 115 decreases thepressure in empty compartment 102, permitting the pressure extended tocompartment 100 to initiate transfer of globule 107 through restrictedpassage 105 to compartment 102. There is, of course, a tendency for thesurface tension forces to assist in transfer of globule 107 intocompartment 102 once transfer through passage 105 has been initiated.

A second input fluid pressure pulse subsequently applied at common inputpath 150 similarly effects transfer of globule 107 from compartment 102back through passage 105 into compartment 100. In this manner theillustrative embodiment of FIG. 1 operates as a binary counter, globule107 from compartment 102 back through passage 105 into compartment 100.In this manner the illustrative embodiment of FIG. 1

operates as a binary counter, globule 107 switching back and forthbetween compartments 100 and 102 in response to successive fluidpressure pulses applied at common input path 150 and providingcorresponding output manifestations at terminals 130 and 132.

As globule 107 passes through passage 105, vent path 115 is blockedthereby. Accordingly, the transfer of energy to globule 107 from aninput fluid pressure pulse applied at input in FIG. 2 in whichindividual vent paths 216 and 2l8 are associated with each ofcompartments 200 and 202, thereby permitting a greater interval forenergy transfer to globule 107. Operation of the embodiment of FIG. 2 issubstantially similar to the operation of the embodiment of FIG. 1described above, successive fluid pressure pulses'applied at commoninput 250 effecting the transfer of globule 207 back and forth betweencompartments 200 and 202. The individual vent path 216 or 218 associatedwith the empty compartment decreases the pressure in the emptycompartment decreases the pressure in the empty compartment such thatthe input pulse issufficient to initiate transfer of globule 207 throughrestricted passage 205 to the empty compartment.

Sensing means, illustratively comprising interrogation port 280 andsensing port 281 in FIG. 2, provide an output manifestation of thelocation of globule 207. Thus, when a fluid pulse is applied at port 280at a time when globule 207 is located in compartment 200, no outputpulse occurs at port 281. On the other hand, when an input pulse isapplied at port 280 and globule 207 is located in compartment 202, thepulse is extended through empty compartment 200 to sensing port 281 asan output manifestation.

The embodiment in FIG. 2 also comprises foraminous interface material211, which may be a porous ceramic or plastic material, for example,disposed in input paths 210 and 212 and in vent paths 216 and 218.Foraminous interfaces 211 prevent globule 207 from entering paths 210,212, 216 and 218 but are porous to fluid pressure flow therethrough.Additionally, interfaces 211 provide further control of the resistanceto input fluid pressure flow in paths 210 and 212.

Although the fluid device embodiments of FIGS. 1 and '2 have beendescribed above in terms of their operation as binary counters inresponse to input pulses, these devices may also be operatedadvantageously as fluid oscillators in response to a continuous fluidpressure input applied at path 150 or path 250. Considering theembodiment of FIG. 1, by way of example, when fluid pressure isinitially applied at input path 150, globule 107 is urged throughpassage 105 into compartment 102 in the manner described above. However,as globule 107 is transferred through passage 105 and enters compartment102, vent path 115 is unblocked. The fluid pressure differential betweencompartments 100 and 102 therefore reverses, the fluid pressure appliedto compartment 100 over path being now decreased by venting through path115. The fluid pressure extended to path 112 from the continuouspressure input at path 150 thus urges globule 107 back through passage105 into compartment 100. Again, as globule 107 is transferred throughpassage 105 vent path 115 is first blocked and then unblocked by theglobule. Movement of globule 107 into compartment 100, unblocking vent115, once again reverses the fluid pressure differential so as toinitiate transfer of the globule back to compartment 102. Oscillation ofglobule 107 between compartments 100and 102 continues in this manneruntil the fluid pressure input at path is terminated.

Another alternative fluid pressure operated switching device embodimentis shown in FIG. 3 which, although it may be operated as a binarycounter in substantially the same manner as the embodiments of. FIGS. 1and 2, is particularly adapted to function as a fluid oscillator. Forthis purpose individual paths 360 and 362 corresponding generally tovent paths 216 and 218 in FIG. 2 are associated with respectivecompartments 300 and 302 and are interconnected via compartment 365.

Compartment 365 functions as a fluid capacitor and, in conjunction withforaminous interfaces 311 and paths 360 and 362, functions as an R-Ccircuit for principally determining the frequency of oscillation of theembodiment of FIG. 3.

According to a further aspect of the invention, additional switchingdevice compartments may be connected in tandem to the basic two-statedevice to provide additional states such as for ring counter operation,n compartments providing n states of operation. For example, anillustrative three-state ring counter embodiment is shown in FIG. 4comprising three compartments 401, 402 and 403. Each compartment isconnected in tandem to the next through a restricted passage;compartment 401 is connected to compartment 402 through passage 421,compartment 402 to compartment 403 through passage 422, and compartment403 to compartment 401 through passage 423. Individual input fluidpressure paths 411, 412 and 413, respectively associated withcompartments 401, 402 and 403 are connected via manifold 451 to commoninput path 450.

Vent paths may be associated with the several compartments in themanner, for example, of the two-state embodiment of FIG. 1 Thus, in FIG.4 vent path 415 disposed in restricted passage 421 is associated withcompartments 401 and 402, vent path 416 is associated with compartments402 and 403, and vent path 417 with compartments 403 and 401. Further,sensing apparatus is associated with each compartment to provide anoutput manifestation of the location therein of liquid globule 407.Illustratively in FIG. 4 globule 407 is assumed to be of conductivematerial and pairs of electrical contacts are disposed in each ofcompartments 401, 402 and 403 so as to be bridged when globule 407 islocated in the compartment, thereby providing corresponding outputmanifestations at respective terminal pairs 431, 432 and 433.

Advantageously, input paths 411, 412 and 413 may be angled or biased inthe desired direction of movement of globule 407 to insure movement ofthe globule in a particular direction around the ring of compartments,such as for counterclock'wise movement as shown, by way of example, inFIG. 4. Thus, when an input fluid pressure pulse is applied at inputpath 450 and extended through manifold 451 to each of input paths 411,412 and 413, globule 407 is urged through restricted passage 421 intocompartment 402 in a manner substantially similar to that described inconnection with FIG. 1 above. A second pulse at input path 450 initiatestransfer of globule 407 from compartment 402 through passage 422 intocompartment 403 and a third input pulse effects transfer of globule 407through passage 423 back into compartment 401. Successive input fluidpressure pulses applied at input path 450 thus advance globule 407through successive ones of tandemly connected compartments 401, 402 and403 in a coun- I Although the embodiments of the drawing have beendepicted illustratively as generally hourglass-shaped structures, itwill be apparent that other shapes may be employed with equal facilityas well as other types of moving elements. For example, the restrictionto passage of the liquid globule between compartments need not be byvirtue of size or shape of the interconnection between the twocompartments but may be by virtue of a suitable foraminous materialinterposed between the two compartments. Moreover, various alternativesexist for moving elements in the form of liquid globules and, in fact,inasmuch as fluid devices are operable at elevated or reducedtemperatures without impairment, the globule need not be liquid atambient temperature. It is to be understood, therefore, that theabove-described arrangements are but illustrative of the application ofthe principles of applicant's invention. Numerous other arrangements maybe devised by those skilled in the art without departing from the spiritand scope of the invention.

lclaim:

l. A fluidic device comprising a housing having two compartmentsseparated by a restricted passage, a movable element disposed in one ofsaid compartments, said restricted passage preventing free movement ofsaid movable element between said two compartments, means for directinginput fluid pressure signals in common to both of said compartments,said directing means including a single input fluid pressure path andpressure path means connecting said input path in common to both of saidcompartments, and vent path means associated with said compartments forventing individual of said compartments when said movable element is notdisposed therein, said vent path means comprising a single vent pathconnected to said restricted passage so as to be blocked by said movableelement during movement of said element through said restricted passage,whereby an input fluid pressure signal applied to said input patheffects movement of said movable element between said two compartmentsthrough said restricted passage.

2. A fluidic device comprising a housing having two compartmentsseparated by a restricted passage, a movable element disposed in one ofsaid compartments, said restricted passage preventing free movement ofsaid movable element between said two compartments, means for directinginput fluid pressure signals in common to both of said compartments,said directing means including a single input fluid pressure path andpressure path means connecting said input path in common to both of saidcompartments, and vent path means associated with said compartments forventing individual of said compartments when said movable element is notdisposed therein, said vent path means comprising an individual ventpath connected to each of said compartments such that each saidindividual vent path is blocked when said movable element is disposed insaid compartment connected thereto, whereby an input fluid pressuresignal applied to said input path effects claim 2 of said movableelement between said two compartments through said restricted passage.

3. A fluidic device in accordance with claim wherein said vent pathmeans further comprises means interconnecting said individual ventpaths.

4. A fluidic device comprising a housing having two compartmentsseparated by a restricted passage, a movable element disposed in one ofsaid compartments, said restricted passage preventing free movement ofsaid movable element between said two compartments, a single input fluidpressure path, pressure path means connecting said input path in commonto both of said compartments, vent path means associated with saidcompartments, said vent path means comprising an individual vent pathconnected to each of said compartments and means including fluidcapacitor means interconnecting said individual vent paths, and meansfor providing an input fluid pressure signal to said input path toeffect movement of said movable element between said two compartmentsthrough said restricted passage.

1. A fluidic device comprising a housing having two compartmentsseparated by a restricted passage, a movable element disposed in one ofsaid compartments, said restricted passage preventing free movement ofsaid movable element between said two compartments, means for directinginput fluid pressure signals in common to both of said compartments,said directing means including a single input fluid pressure path andpressure path means connecting said input path in common to both of saidcompartments, and vent path means associated with said compartments forventing individual of said compartments when said movable element is notdisposed therein, said vent path means comprising a single vent pathconnected to said restricted passage so as to be blocked by said movableelement during movement of said element through said restricted passage,whereby an input fluid pressure signal applied to said input patheffects movement of said movable element between said two compartmentsthrough said restricted passage.
 2. A fluidic device comprising ahousing having two compartments separated by a restricted passage, amovable element disposed in one of said compartments, said restrictedpassage preventing free movement of said movable element between saidtwo compartments, means for directing input fluid pressure signals incommon to both of said compartments, said directing means including asingle input fluid pressure path and pressure path means connecting saidinput path in common to both of said compartments, and vent path meansassociated with said compartments for venting individual of saidcompartments when said movable element is not disposed therein, saidvent path means comprising an individual vent path connected to each ofsaid compartments such that each said individual vent path is blockedwhen said movable element is disposed in said compartment connectedthereto, whereby an input fluid pressure signal applied to said inputpath effects claim 2 of said movable element between said twocompartments through said restricted passage.
 3. A fluidic device inaccordance with claim wherein said vent path means further comprisesmeans interconnecting said individual vent paths.
 4. A fluidic devicecomprising a housing having two compartments separated by a restrictedpassage, a movable element disposed in one of said compartments, saidrestricted passage preventing free movement of said movable elementbetween said two compartments, a single input fluid pressure path,pressure path means connecting said input path in common to both of saidcompartments, vent path means associated with said compartments, saidvent path means comprising an individual vent path connected to each ofsaid compartments and means including fluid capacitor meansinterconnecting said individual vent paths, and means for providing aninput fluid pressure signal to said input path to effect movement ofsaid movable element between said two compartments through saidrestricted passage.